Here’s a quick demo of a pedigree chart drawn using HTML5 Canvas:
The code was pretty much just thrown together; if I were to use this in an actual app, it’d be much cleaner. And for some reason it doesn’t quite work in Safari 4, so you’ll need to use Firefox 3.5.
As for next steps, I’m going to try to rewrite the demo using Processing.js. I’m also planning to extend it to allow panning (so you can have a huge pedigree chart onscreen — some of the Flash-based pedigrees out there do the same thing), and I’m itching to do some kind of genealogy demo ala Snow Stack (Safari only).